A series of related developmental studies are designed to elucidate eating behavior patterns in human infants and children, how these patterns relate to indices of obesity, and how other variables such as the activity level of infants, the work of feeding of infants, and maternal informational feedback while bottle feeding, may relate to feeding and/or obesity. In Study 1, 150 infant Ss will be monitored regarding sucking behavior from 2 weeks through 5 months of age to ascertain: (a) if the reported association between eating behavior ("obese eating style") and obesity found in adults and children also obtains in infancy; and (b) whether infant feeding patterns may predict later overweight at 6 and 12 months. In Study 2, 75 infant Ss from Study 1 will be assessed, at 18 months of age, regrading self-feeding behavior and child growth indices, as will parental eating behavior and growth indices. The goal is to determine the relationship between infant sucking behavior and later eating patterns, and between child and parental eating patterns, relating these factors to indicies of obesity. Study 3 will measure early infant activity and determine if a relationship exists between activity, feeding patterns and indices of obesity. Study 4 will examine how the amount of exertion required during feeding affects the amount consumed by heavy infants. Study 5 investigates the influence of maternal informational feedback while bottle feeding on consumption, using an opaque, externally weighted bottle disguising the amount of formula within. Results from these studies should clarify factors in the development of obesity, and thus may permit identification of those infants at risk to develop obesity and provide the necessary background for development of early intervention procedures in this important health problem.